When packaging articles, such as bottles or cans, into a carton or other suitable container, the articles are typically separated into discrete groups and each group of articles is then placed into a carton. Frequently, an insert or partition is placed between the articles to prevent the articles from colliding into each other and causing damage to the integrity of the articles or damage to the graphics on the articles. The partitions may serve other functions as well, such as forming part of the carton. The partitions are placed between the articles after the articles have been separated into a discrete group but before the articles are placed into the cartons.
In a typical packaging machine, a partition feeder holds a stack of the partitions in a supply hopper. The stack of partitions are formed between two sides of the supply hopper and rest against the bottom of the hopper. The stack is releasably retained within the supply hopper by a set of tabs which contacts the first partition in the stack. The stack of partitions are biased toward the tabs by either the weight of the stack and/or by a pusher or other similar type of mechanism which pushes the rear end of the stack.
A selecting apparatus typically has a set of vacuum cups which move forwardly against the first partition and then move away from the partition feeder in order to remove the one partition from the stack. The tabs are carefully positioned so that they permit the removal of the first partition by the vacuum cups but prevent the other partitions from being removed along with the first partition. After removing the partition, the selecting apparatus releases the partition from the vacuum cups and places the partition between adjacent articles in a discrete group.
The ability of the selecting apparatus to pick a single partition is influenced by a number of factors, including the extent to which the tabs contact the partitions, the pressure in the vacuum cups, and the force applied through the partitions to the tabs. With many partition feeders, the stack is formed at a downward angle so that the weight of the stack itself generates a force at the tabs. This force is necessary to ensure that subsequent partitions are advanced into the proper position after previous partitions have been removed by the selecting apparatus. The force is also necessary so that vacuum cups in the selecting apparatus do not knock the partitions out of position when they move against the first partition for a pick. The magnitudes of the pressure in the cups, the force at the tabs, and the amount of tabbing must be fairly accurately set in order for the selecting apparatus to consistently and reliably remove a single partition from the supply hopper.
The advancement of the partitions, however, may be hampered by the supply hopper. For instance, the surfaces of the sides and bottom of the supply hopper frictionally engage the partitions rendering it difficult for the partitions to advance. At times, a gap forms between adjacent partitions due to one partition advancing at a different rate than the other partition. These gaps disrupt the order of the stack and affect the magnitude of the force applied by the stack against the tabs. Also, during the refilling of the supply hopper, the partitions may fall down so that the fronts of the partitions face the bottom of the supply hopper. It was therefore difficult with existing supply hoppers to ensure that the partitions remain in alignment with each other.
The supply hopper may present additional problems. Due to the friction generated by the sides and bottom of the supply hopper, a relatively large force must be used to overcome the frictional engagement of the supply hopper. This relatively large force, in turn, requires that the tabbing be heavy, i.e. must extend further into the partitions, and that the pressure in the cups be large so that a partition can be removed from the heavy tabbing. Because the partitions are being subjected to a heavy tabbing and a large pressure, the partitions must be strong enough so that they do not tear or otherwise become damaged. The packaging machines are therefore limited in the types of partitions that can be used in the cartons.
In order to maintain a sufficient force at the tabs, the weight of the stack should not fall below a certain amount. Consequently, during operation of the partition feeder, an operator must periodically refill the partition feeder so that the stack stays above this certain amount. When the packaging machine operates at faster rates, the partition feeder must be more closely supervised by the operator since the partitions are removed from the supply hopper at a quicker rate. A need therefore exists in the industry for a partition feeder which requires less supervision and which is therefore less labor intensive.
The partition feeders are typically mounted above the flow of articles, with the supply hopper being about 7 or 8 feet above the ground. The operators of the partition feeder therefore need a step ladder or some type of raised platform with steps in order for the operator to add the partitions to the supply hopper. The time and energy expended by the operator in going up and down the steps further burdens the operator and results in an overall more costly packaging operation.
Many packaging machines can only package one size of articles and just one configuration of articles. For instance, a packaging machine might be limited to just a standard American size bottle that is packaged into a 12 pack container. Another packaging machine would be designed to package articles having a different size article or to package articles into a different size container.
Some recently manufactured packaging machines, however, have some flexibility in that they can package articles of different sizes into various types of containers. While these machines may have the capability, it is relatively difficult to adjust the packaging machines to package another article size or another configuration. The adjustments necessary on the packaging machines include an adjustment in the partition feeder for a different size partition. This adjustment might encompass the replacement of one supply hopper with a supply hopper that could hold the new partitions. A need therefore exists in the industry for a partition feeder that can supply partitions of different sizes.